Geneva - Mar 31, 2008 - Numonyx, a joint venture of ST Microelectronics and Intel, is working on making a nearly 40-year-old concept a reality: Phase change memory (PCM). Samples of the company's efforts in memory technology were released earlier in March. PCM provides very fast read and write speeds at lower power than conventional flash, and allows for bit alterability normally seen in RAM. PCM also uses less power. PCM chips can survive tens of millions of read-write cycles.
CNET explains that PCM chips heat a microscopic bit on a substrate to between 150 degrees and 600 degrees Celsius. The heat melts the bit, which when cooled solidifies into one of two crystalline structures, depending on how fast the cooling takes place. The two different crystalline structures exhibit different levels of resistance to electrical current, and those levels of resistance in turn are then read as ones or zeros.